Study On Properties Of Al₂O₃ Thin Films Deposited By Magnetron Sputtering And Application

Al2O3 thin films are widely used in mechanics, optics and microelectronics because of their excellent properties, in terms of chemical inertness, mechanical strength, hardness, transparency, high abrasive and corrosion resistance, anti-laser-induced damage, as well as insulation and optical properties. The applications and preparation of Al2O3 thin films are introduced in this paper.Al2O3 films have being deposited using various methods including magnetron sputtering deposition, pulsed laser deposition, ion assisted deposition, electron beam physical vapor deposition, chemical vapor deposition, sol-gel method etc. However, it is still a question how to determine sputtering process parameters, microstructure and properties of thin films.In this paper, Al2O3 films were deposited by reactive magnetron sputtering in Ar/O2 mixture gases on the optical glass K9 and silicon substrate. According to the national standards of measurement requirement, tape with 2cm wide and no less than 2.74N/cm peeling strength was glued to the surface of the film. After perpendicular and quick pulling, the films are not ramous. So the adhesion of thin films is good. We analyzed of processing parameter on depositing rate of Al2O3 films. It indicated that, the O2 concentration and target power make a notable impact on deposition rate. Ellipsometry was used to determine the optical properties of Al2O3 films. The refractive index and extinction coefficient of Al2O3 film is 1.57-1.62 and 0-1.0×10-3 respectively at the visible light under the deposition condition of Ar flow rate in 45sccm and O2 in 18sccm. The film deposition rate is 0.07 nm/s. XRD was applied to analysis the structure of Al2O3 films. It was found that the deposited film without annealing was amorphous, and different processing parameters can also influence the structure of films. The surface morphology was observed by SEM, the influence of the change upon the thin film facial look of craft parameter. XPS was used to analyze the composition of Al2O3 films. The O/Al ratio in the deposited film is in the vicinity of 1.5,the results showed that Al2O3 films were pure。The result showed that the deposition rates, optical properties, and laser anti-damaged properties of Al2O3 thin films are dependent on the process parameters used such as O2 concentration, target power, sputtering pressure, and target-substrate distance.